The present invention relates in general to exhaust extraction systems for emergency vehicles, such as a fire truck or ambulance. More particularly, the present invention relates to the design of an extension sleeve that includes baffles to deflect and direct the vehicle exhaust.
Emergency vehicles, such as a fire truck, create an interesting exhaust-removal challenge due to the nature and manner of use of the vehicle in preparation for an emergency run. A fire truck is usually backed into the fire house garage bay and readied for its next run in this manner. When an alarm call comes in, the engine of the fire truck is started by the driver while he waits for everyone to put on their turn out gear and get on board. During this brief time interval before the truck leaves the station, the engine is cold and generates the dirtiest exhaust gases which need to be vented to the outside atmosphere.
The exhaust system of a fire truck is typically arranged so that the “tail” pipe exits from the right side of the truck in front of the rear axle. While this location places the exiting exhaust gases near the center of the fire house, it is an advantageous location for present day exhaust extraction systems. For the most part these present day exhaust extraction systems use a flexible exhaust hose which is connected at one end to the fire truck exhaust pipe and at the opposite end to an overhead duct which leads out of the fire house. A high pressure blower is used to forcibly remove the exhaust gases from the fire house. A hose adapter or nozzle assembly of some type is typically used to connect the flexible hose to the exhaust pipe. With secure and sealed connections and so long as there are no perforations or open seams in the exhaust extraction system, all of the vehicle exhaust gases will be safely vented out of the fire house and into the atmosphere. The use of a flexible hose to remove exhaust gas from a running engine is not new. Automobile mechanics have used such hoses for years. However, there is one important difference between use by a mechanic and use as part of an exhaust extraction system which is attached to an exhaust pipe of a fire truck. Once everyone is onboard the fire truck, it is ready to leave the fire house and there is usually no one left to disconnect the exhaust hose from the exhaust pipe. Even if personnel were left behind, safe handling of the vehicle exhaust would dictate that the vehicle be pulled out of the fire house and then have the hose removed. This would involve a start up and stop procedure at the very time the fire truck is trying to leave quickly on the emergency run. Even if someone was left behind and could disconnect the exhaust hose prior to the fire truck departing, this would allow exhaust gas to be dispersed into the fire house, the very event which exhaust extraction systems are designed to prevent.
In order to address this disconnect concern, present day exhaust extraction systems try to provide an automatic disconnect feature such that the adapter or nozzle connecting the flexible hose to the exhaust pipe comes off automatically after the fire truck has reached the door of the fire house. While present exhaust extraction systems which are offered commercially have approached this design challenge in slightly different ways, most systems provide an extra length of flexible hose which is held by a saddle and suspended from an overhead track by means of a spring-biased balancer. The spring-biased balancer supports the hose and the induced spring-tension force facilitates the release of the hose from the exhaust pipe as the fire truck leaves the fire house. As the fire truck begins to pull out of the fire house, the distance between the exhaust pipe and the duct work connection increases. This pulls on the flexible hose which in turn pulls the balancer down the track toward the door. The loop of excess hose between the balancer saddle and the duct hose connection allows this movement. When the balancer reaches the track stop, the balancer cable begins to uncoil which increases the resisting spring force. At some point, the resisting spring force of the balancer becomes greater than the force needed to separate the adapter from the exhaust pipe. Continued travel of the fire truck causes the hose adapter/nozzle to separate from the exhaust pipe.
In 1999, U.S. Pat. No. 5,927,759 was issued to Hyslop and is directed to a unique connection assembly for an exhaust extraction system. The structure disclosed in the '759 patent is disclosed herein as part of the description of the present invention.
In terms of fire truck exhaust pipe arrangements, some vehicles include a curved or angled section that directs the exhaust downwardly and rearwardly in the direction of the rear wheel. When this style of exhaust system is to be fitted with the style of connection assembly disclosed in the '759 patent, it is necessary to cut off the curved or angled section of the exhaust pipe. This is required because the annular sleeve component of the '759 patent is designed to fit onto a straight, cylindrical pipe section, not a curved or angled section.
Once this curved or angled section is removed, the vehicle exhaust is directed outwardly from the side of the vehicle, not downwardly and rearwardly as is desired. While there is no issue or concern when the flexible exhaust hose is connected, the problem arises when the exhaust hose and nozzle (24) of the '759 device are pulled free as the fire truck leaves the fire house. Once these portions are pulled off, what is left is a straight conduit assembly connected to the straight pipe section. As such, the fire truck exhaust is directed outwardly, not downwardly and rearwardly. As fire fighters have to work around the fire truck, directing the hot exhaust outwardly instead of downwardly and rearwardly is a problem that needs a solution.
The present invention provides an improvement to the '759 patent, by configuring the insert sleeve that remains with the fire truck with a series of baffles that allow the fire fighters to orient the insert sleeve and thereby direct the baffles so that the exhaust is deflected and directed in the desired direction, preferably downwardly and/or rearwardly.